Le Chatelier's Principle Review Lab Chem

Why is equilibrium called a dynamic state?

• Chemists try to convert as much reactants as possible into products.
• The reactions at equilibrium continue to take place once equilibrium is established.
• The products of a forward reaction are favored, so equilibrium lies to the right.
• All chemical reactions are considered to be reversible under suitable conditions.

At what time (in seconds) is equilibrium established?

• 0 seconds
• 1 second
• 5 seconds
• 10 seconds

Le Chaltelier's Principle states that if a chemical system at equilibrium is stressed,

• the system will adjust to increase the stress
• the system will adjust to reduce the stress
• the system will not adjust

When writing an endothermic reaction, heat energy is stated as

• product
• catalyst
• reactant

An exothermic reaction is allowed to reach equilibrium. If heat energy is then removed, the equilibrium will shift

• toward the middle
• toward the reactant side
• toward the product side

Which of the following is NOT true at equilibrium?

• The forward and reverse reactions proceed at the same rate.
• The concentrations of reactants and products do not change.
• The concentration of the reactants is equal to the concentration of the products.
• The forward and reverse reactions continue to occur.

For the reaction...
SO_2(g) + O_2(g) <−>  SO_3(g)
If the concentration of SO_2(g)  is increased, the equilibrium of the reaction will ___________.

• shift to the left
• shift to the right
• not shift

For the reaction...
SO_2(g) + O_2(g) <−>  SO_3(g)
If the equilibrium shifts to the right, the concentration of O_2(g) will ___________.

• increase
• decrease
• remain the same

For the reaction...
energy +  N_2(g)  +  O_2(g)  <−>  2NO_(g)
If  O_2(g) is removed, the  concentration of N₂ will _______.

• increase
• decrease
• remain the same
• double

A +  B <--> C + D   ΔH= 151kJ
Rewrite the above equation with energy as a reactant or product:

• A +  B <--> C + D + energy
• A +  B + energy <--> C + D